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Biomedical subjects

S Fujiwara

Publications and source records attributed to S Fujiwara.

At least 235 records · Page 13Linked to original sources
PubMed1995

Human type VI collagen: purification from human subcutaneous fat tissue and an immunohistochemical study of morphea and systemic sclerosis.

Collagen was isolated from human placenta by pepsin digestion and salt precipitation. This collagen was similar in its electrophoretic mobility and immunological reactivity with monoclonal antibody to form B of type VI collagen in the literature (Trueb B, Schreier T, Bruckner P and Winterhalter K. 1987. Eur. J. Biochem. 166: 699-703). We prepared polyclonal rabbit antiserum against alpha 2 chain of type VI collagen and performed an immunohistochemical study using this polyclonal antibody. It reacted in fat tissue and around vessels and peripheral nerves in normal human skin. To confirm the presence of type VI collagen in fat tissue, we isolated collagen from human subcutaneous tissue. This collagen showed a similar pattern in polyacrylamide gel electrophoresis with that from human placenta and cross-reacted with monoclonal or polyclonal antibody against type VI collagen. By immunohistochemical staining, abundant type VI collagen was observed in the septum of subcutaneous fat tissue in morphea or systemic sclerosis. In the mild hyalinizing areas or after treatment with 6M urea or hyaluronidase in highly hyalinized areas, the staining of type VI collagen increased. These data suggest that the amount of type VI collagen in subcutaneous tissue is involved in the early phases of these fibrosing disorders and that type VI collagen accumulates even more in hyalinizing tissue in late phases of these diseases.

Adipose Tissue↗
PubMed1995

Pharmacology of a non-selective ETA and ETB receptor antagonist, TAK-044 and the inhibition of myocardial infarct size in rats.

1. The aims of the present study were to characterize the pharmacological profile of a new endothelin (ET) receptor antagonist, TAK-044 and to consider whether it limits the extension of myocardial infarct size in rats. 2. Binding of [125I]-ET-1 to ET receptors on rabbit ventricular and cerebellar membrane fractions was inhibited by TAK-044 with IC50 values of 3.8 nM and 130 nM, respectively. 3. It inhibited ET-1, ET-2 and ET-3-induced vasoconstriction of porcine isolated coronary arteries in a competitive (ET-1, ET-2) and a non-competitive (ET-3) manner. 4. In the rat in vivo, the ET-1-induced blood pressure changes including transient hypotension followed by sustained hypertension, were inhibited by TAK-044 (0.1-10 mg kg-1, i.v.) in a dose-dependent manner. 5. Acute myocardial infarction induced by 1 h coronary occlusion followed by 24 h reperfusion in rats caused an infarct size of 60 +/- 2% (n = 12) of the area-at-risk by weight. 6. Intravenous injection of TAK-044 10 min before coronary occlusion reduced the infarct size in a dose-dependent manner: 32% and 54% reductions at 1 and 3 mg kg-1, respectively. 7. TAK-044 administered 10 min before or 1 h after reperfusion (1 mg kg-1, i.v.) showed similar inhibitory effects: 34% and 23% reductions, respectively. 8. We conclude that TAK-044 is an ETA/ETB receptor antagonist which shows strong inhibitory effects on the extension of myocardial infarct size after coronary artery occlusion-reperfusion in rats.

Animals↗
PubMed1995

Isolation of Epstein-Barr virus-infected clones of the human T-cell line MT-2: use of recombinant viruses with a positive selection marker.

Certain classes of human T-cell lymphomas have been shown to be persistently infected with Epstein-Barr virus (EBV). To achieve an experimental system of persistent EBV infection in T cells, we used EBV recombinants with a positive selection marker. Infection of the human T-cell line MT-2 with EBV recombinants that had a hygromycin resistance gene and subsequent selection with this drug permitted isolation and long-term maintenance of EBV-infected MT-2 clones. For each clone, essentially 100% of cells were positive for EBV nuclear antigen. These MT-2 clones harbor monoclonal episomes of EBV DNA and stably express two EBV latent proteins, EBV nuclear antigen 1 and latent membrane protein 1. The growth of these EBV-infected MT-2 clones was slower than that of uninfected clones, suggesting that EBV affects regulation of T-cell proliferation. EBV recombinants with a positive selection marker will be a useful tool in establishing experimental systems of persistent EBV infection in certain non-B-cell lineages.

Cell Line↗
PubMed1995

Establishment of cell lines from multipotent epithelial sheet in the budding tunicate, Polyandrocarpa misakiensis.

We report here the in vitro culture of the atrial epithelium, which is the major formative tissue of the budding tunicate, Polyandrocarpa misakiensis. Preliminary studies suggested that both pH and osmotic pressure of the basic seawater medium should be lowered significantly (pH 6.8, 800-830 mOsm). In the growth medium consisting of modified millipore-filtered seawater, Dulbecco's modified Eagle medium and 3% fetal bovine serum, cells spread out from the epithelial explant and proliferated with a doubling time of about 13 hours. They could be cloned and cultured successively. They contained the Polyandrocarpa lectin gene, showing that they were indeed of tunicate origin. At a low cell density (< 3 x 10(2) cells/mm2), clonal cells took a spherical form and contained several granules in the cytoplasma. At a high cell density (> 3 x 10(4) cells/mm2), on the other hand, they gave rise to smaller cells without any specialized features and, finally, to dark flattened cells. Consistent with this observation, confluent cells lost the atrial epithelium-specific antigen, which reappeared on the cell surface when they were re-plated at a low density. In conclusion, we have established for the first time tunicate cell lines. They appeared to differentiate and dedifferentiate repeatedly in our culture system.

Animals↗
PubMed1995

[Assessment of right ventricular function by magnetic resonance imaging of old myocardial infarction].

The usefulness of magnetic resonance imaging (MRI) for estimating right ventricular function and the influence of left ventricular dysfunction on the performance of the right ventricle were assessed in 43 patients with chronic myocardial infarction (MI) and 14 control subjects (N) using electrocardiography-gated MRI and cardiac catheterization. Patients with MI were divided into three groups according to the location of the coronary lesions; 22 patients with left coronary artery lesion (LCA group), 13 with right coronary artery lesion (RCA group), and 8 with both left and right coronary artery lesions (L+R group). The right ventricular end-diastolic volume (RVEDV) and right ventricular ejection fraction (RVEF) were measured by Simpson's rule algorithm on transverse images of the right ventricle obtained at the end-systolic and end-diastolic phases. In 34 of the 43 patients, the same parameters of right ventricular function were calculated by the thermodilution method using a Swan-Ganz catheter with rapid response thermistor. Left ventricular ejection fraction (LVEF) and end-diastolic volume were determined from left ventriculography. The intraobserver reproducibility (11 cases, r = 0.97) and interobserver reproducibility (11 cases, r = 0.92) of RVEF measured by MRI were excellent. The RVEF and RVEDV determined from MRI were significantly correlated with those from the thermodilution method (RVEF: r = 0.56, RVEDV: r = 0.52). There was no difference in right ventricular end-diastolic volume index in any patient group. The RVEF was decreased in the L+R (41.0 +/- 4.5%, p < 0.01) and RCA (45.9 +/- 6.6%) groups, but there was no difference between the LCA (50.6 +/- 6.6%) and N (48.9 +/- 4.3%) groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

[Interhemispheric differences of the middle latency auditory evoked magnetic fields revealed by a whole head magnetoencephalography system].

It is known that the auditory evoked N100m response appears faster in the contralateral hemisphere than in the ipsilateral hemisphere to the stimulated ear. For the middle latency response named P50m, however, there have been only few studies with controversial findings. In the present study, auditory evoked responses to the unilateral tone stimuli were measured in 36 right-handed normal subjects, using a helmet-shaped whole head magnetoencephalography system. In a total of 72 hemispheres of 36 subjects, P50m dipolar patterns were observed statistically (p > 0.02) frequently in the contralateral hemispheres (63.9%) compared to the ipsilateral hemispheres (43.0%). N100m dipolar patterns were observed over both left and right hemispheres either by left or right ear stimuli. Peak latency of the P50m was statistically (p < 0.02) shorter in the contralateral hemisphere (45.0 +/- 8.5ms, mean +/- s.d.) compared to the ipsilateral hemisphere (54.4 +/- 11.5ms). Peak latency of the N100m was also statistically (p < 0.001) shorter in the contralateral hemisphere. Moreover, when compared between contralateral responses, the left-ear stimulated right-hemispheric response (84.6 +/- 8.4) was statistically (p < 0.05) faster than the right-ear stimulated left-hemispheric response (89.3 +/- 10.2ms). These results indicate that contralateral auditory cortex dominates the ipsilateral cortex at the middle as well as the long latency components. Moreover, at least for pure-tone stimuli, right hemispheric dominance was indicated for the N100m responses. The whole-head MEG system is suitable to analyze small but significant interhemispheric difference of auditory function.

Adult↗
PubMed1995

[Surgical decompression for massive cerebellar infarction].

The authors report 10 patients with progressive neurological deterioration due to massive cerebellar infarctions. Computerized tomography scans confirmed obstructive hydrocephalus and brain stem compression. All 10 patients (seven men, three women; mean age, 59 years) were treated by external ventricular drainage and decompressive suboccipital craniectomy. After discharge from the hospital, they were followed up (23-101 months) and their functional independence was evaluated by the Barthel Index. The condition of three patients with brain-stem infarction had deteriorated despite decompressive surgery. Two of these died during the acute stage and one because severely disabled. The remaining seven patients showed neurological improvement during the postoperative period. Four patients with preoperative Japan Coma Scale of 100 returned to their previous jobs within the follow-up period and three patients with preoperative Japan Coma Scale of 200 required some assistance in daily activities. It is suggested that decompressive surgery may be beneficial for massive cerebellar infarction. The postoperative prognosis depends mainly on the presence or absence of coexisting brain-stem infarction. It is possible that, without brain-stem infarction, patients who remained in a "dependent" state may have recovered better if they had been operated on earlier.

Aged↗
PubMed1995

[Experiences of the approaches to heart for a patient with a tracheostoma].

The performance of open heart surgery in a patient with a tracheostoma can present difficult problems, including postoperative mediastinitis and inadequate operative exposure. Recently, we experienced two cases in which tracheostomy had been done preoperatively due to heart failure and reported the satisfactory results in this paper. Case 1; A 59-year-old woman who had mitral stenosis and massive regurgitation received mitral valve replacement and left atrial raphy. The approach to heart was performed in according to the following. A transverse submammary skin incision was made from right anterior axillar line to left mammary line and then a bilateral thoracotomy was made at the fourth intercostal space. Case 2; A 73-year-old man who had old myocardial infarction and postinfarction angina received coronary artery bypassgrafting to right coronary artery and left anterior descending branch, using saphenous vein grafts. A skin incision was placed at the second intercostal space in the fashion of "collar skin incision" and then made from the center of collar skin incision to the xiphoid process. The sternum was transected at the second intercostal space and divided longitudinally to the xiphoid process. These two approaches provided the adequate operative field. The cannulation of the ascending aorta, the superior vena cava and the inferior vena cava presented no difficulty and the operative procedure could be performed easily in a routine manner. We think that in a case of open heart surgery of a patient with a tracheostoma the approach in which the skin incision is distant from the area of a tracheostoma and no dissection near a tracheostoma is necessary have to be selected in order to decrease the risk of postoperative wound infection and mediastinitis.

Aged↗
PubMed1995

[99mTc-ECD dynamic SPECT in "luxury perfusion" of subacute stroke].

To evaluate the cerebral pharmacokinetics of 99mTc-ethyl cysteinate dimer (99mTc-ECD) at blood flow levels beyond the normal range, we investigated "luxury perfusion" in subacute stroke, ictal hyperperfusion in epilepsy and post-decompressive hyperemia in head trauma. All 7 patients showed a hyperactive area on SPECT studies using 99mTc-HM-PAO. 99mTc-ECD static image demonstrated a hyperactive area in both epilepsy and head trauma, and a hypoactive area in "luxury perfusion." On the dynamic SPECT of 99mTc-ECD in both epilepsy and head trauma, brain distribution of the tracer was determined within 2 min. postinjection and remained stable for up to 1 hour; however, "luxury perfusion" area showed a change from initial hyperactivity to late hypoactivity with the passage of time. The time activity curve in "luxury perfusion" area demonstrated a steep decrease of counts/pixel for up to 4-5 minutes postinjection, and a moderate decrease in the following phase. The early wash-out mechanism of 99mTc-ECD from "luxury perfusion" area can be described by a biexponential function including an initial steep decrease representing the rapid loss of the lipophilic complexes which were not metabolized in injured brain tissue.

Acute Disease↗
PubMed1995

Role of endogenous endothelin in the extension of myocardial infarct size studied with the endothelin receptor antagonist, TAK-044.

The effects of TAK-044 on the extension of ischemia/reperfusion-induced myocardial infarction were studied in rats. Acute myocardial infarction was induced by occlusion of the left coronary artery for 1 h followed by reperfusion for 24 h. Infarct size and the area at risk were determined histochemically. Infarct size as a percentage of the area at risk (IS) was significantly reduced in a dose-dependent manner by TAK-044 administered 30 min before reperfusion (0.3-3.0 mg/kg, i.v.). Size-limiting effects similar to those in rats were also obtained in rabbits and dogs. In addition, TAK-044 administered 3 h after reperfusion also reduced the IS significantly. Preconditioning (5 min of LAD occlusion preceding 1 h of coronary occlusion) inhibited the extension of the IS. These effects of preconditioning and TAK-044 were inhibited by glibenclamide (0.1 mg/kg, i.v.; an inhibitor of the ATP-sensitive K channel) but not by DPCPX (1 mg/kg, i.v.; an adenosine A1 receptor antagonist). These results indicate that endogenous endothelin plays an important role in the extension of myocardial infarction and that the cardioprotective effects of TAK-044 can be partially explained by a mechanism similar to that of preconditioning in rats.

Animals↗
PubMed1994

Post-transcriptional regulation of the Pseudomonas aeruginosa algC gene.

The algC gene (encoding phosphomannomutase) of Pseudomonas aeruginosa, similarly to the algD gene, is environmentally regulated through transcriptional activation of its promoter. This gene, like algD, has a long (244 bp) 5' untranslated leader region (5' UTR). Using transcriptional and translational algC::lacZ fusions, we show that even though the transcript levels are similar, the beta-galactosidase-specific activities of the translational fusions are much higher than those of the transcriptional fusions during the entire growth phase. Both the 5' UTR and the ribosomal-binding site are shown to be important for efficient translation of the algC mRNA.

Carbohydrate Dehydrogenases↗
PubMed1994

Identification of chicken liver mitochondrial alanine:2-oxoglutarate aminotransferase and its response to starvation.

In chicken liver, alanine:2-oxoglutarate aminotransferase was located only in the mitochondria. In 40-day-old chickens, starvation resulted in a dramatic increase of liver mitochondrial alanine:2-oxoglutarate aminotransferase activity, reaching about a 100-fold increase in the activity (units/g of liver) on Day 7 of starvation. The mitochondrial alanine:2-oxoglutarate aminotransferase was purified to homogeneity and characterized from the mitochondrial extract of 7-day-starved chicken liver. The enzyme possessed alanine:glyoxylate aminotransferase activity and was also present in control chicken liver. The enzyme was found in the present study for the first time and named alanine:2-oxoglutarate (glyoxylate) aminotransferase. Alanine:2-oxoglutarate aminotransferase specific for alanine and 2-oxoglutarate as substrates was not detected in both control and starved chicken livers. In contrast, liver mitochondrial alanine:2-oxoglutarate aminotransferase from mammals did not possess alanine:glyoxylate aminotransferase activity. The increase in mitochondrial alanine:2-oxoglutarate aminotransferase activity during starvation was found to be attributed to an increase in enzyme protein.

4-Aminobutyrate Transaminase↗
PubMed1994

The gene for ribosomal protein L27 is located on the plastid rather than the nuclear genome of the chlorophyll c-containing alga Pleurochrysis carterae.

The gene for ribosomal protein L27 (rpl27) has not been found in plastid genomes. We report here that the rpl27 gene is located in the plastid genome of the prymnesiophyte Pleurochrysis carterae. The deduced amino acid sequence showed 59% identity with E. coli L27. 1.0 kb transcript of the gene was detected by Northern blot analysis. Nucleotide sequence analysis of PCR products suggested that rpl27 is widespread in the genomes of Prymesiophyta and Rhodophyta. In all species of Prymnesiophyta examined in this study, the gene is located at the 3' downstream region of Rubisco operon.

Amino Acid Sequence↗